Monthly Archives: July 2019

I am retiring on July 1st after nearly 38 years working for UC Cooperative Extension and over 36 years as an Orchard and Environmental Horticulture (EH) Advisor in Sutter-Yuba Counties. What an honor to work with all of you growers, PCAs, and others in the Ag industry, and such a privilege to collaborate with so many talented UC colleagues solving challenging problems together. Continue reading →

During about the second or third week in June, many Howard walnut trees experienced nut drop of perhaps as many as 100 nuts per tree, with many trees losing no more than 60 nuts per tree. These nuts were full size with the shell beginning to harden. Cutting open an immediately dropped nut, you could see darkening of the inside watery kernel material. Several possible causes are explored in this article. Continue reading →

There are several biological factors and non-biological conditions that cause “gumming” in almonds. “Gummy nuts” may refer to different symptoms depending on which part of the fruit is affected. In this article, the term “hull gummosis” refers to the exudates … Continue reading →

There are plenty of benefits that can come from cover cropping in an almond orchard, including improved orchard access, improved water infiltration, encouraging native pollinizers and improved honeybee health. But all the options of species to plant can be overwhelming. Herein we’ll review how to pick a cover crop seed blend for a particular orchard. Continue reading →

Early hull split, when the hull begins to open at the suture, is a don’t-want-to-miss timing in almond production. The crack in the hull does two things: releases nut volatiles so the navel orangeworm (NOW) female can find the nut … Continue reading →

The good news is that a truly sound IPM program should already have you considering economic costs and returns when making pest management decisions. Economic treatment thresholds for pest management can be distilled into a formula that considers the following: … Continue reading →

Sure, you can harvest your walnuts this fall without application of any ethephon. Forgoing the ethephon application would save you material and spray costs. However, despite the costs of application, use of ethephon may wind up saving you money in … Continue reading →

A sudden autumn freeze event last November is the likely cause of widespread dieback observed in both young and mature orchards in the Sacramento and northern San Joaquin Valleys this spring. Following reports in April of walnut orchards not leafing out, our initial diagnosis was freeze damage. We advisors, specialists, and faculty agree that this initial diagnosis has been further supported after examining additional orchards and weather station sites. Continue reading →